This invention relates to granular detergent compositions which are capable of providing superior performance during conventional textile laundering and cleaning operations. The compositions of this invention contain as essential components a water-insoluble aluminosilicate ion exchange material, an organic surface active agent, an alkali metal oxide silicate solid with a SiO.sub.2 :alkali metal oxide weight ratio of from about 1.4:1 to 1.9:1 and a hydratable water-soluble salt of an organic carboxylic acid having at least one ionization constant of less than about 1.0.times.10.sup.-3.
The use of water-insoluble synthetic aluminosilicates in detergent compositions in combination with organic surface active agents is described in British Pat. No. 1,429,143. The compositions of British Pat. No. 1,429,143 and indeed all laundry detergent compositions, generally require the presence of a metal corrosion inhibitor to protect the washing machine and also generally require an agent to render granules crisp so as to confer free-flowing characteristics. In typical granular detergent compositions, satisfactory corrosion inhibition and granule crispness are obtained through the incorporation of sodium silicate in an amount of from about 8% to about 20%. For optimum granule crispness a SiO.sub.2 :Na.sub.2 O weight ratio of from about 2.2:1 to about 3.5:1 is generally employed. U.S. Pat. No. 3,985,669 issued Oct. 12, 1976, describes the incorporation of from about 0.5% to about 3% of sodium silicate in detergent compositions containing aluminosilicate ion exchange materials. This patent points out that the use of higher levels of silicate solids in combination with aluminosilicates can present fabric deposition problems due to insolubility of the components.
U.S. Pat. No. 3,801,511, issued Apr. 2, 1974, discloses compositions and a process for making compositions that are crisp, free-flowing detergent granules containing 10% to 80% sodium carbonate and from 1% to 20% of an anti-caking agent characterized by having a greater solubility in water than sodium carbonate. Preferred anti-caking agents are sodium acetate, sodium citrate and potassium carbonate.
The co-pending commonly assigned patent application of Tom Ohren and Burton H. Gedge III entitled DETERGENT COMPOSITION, U.S. Ser. No. 670,474 filed Mar. 25, 1976, discloses detergent compositions containing magnesium insensitive surface active agents, detergency builders having affinity for calcium ions such as aluminosilicate or salts of citric acid and alkali metal silicates having an SiO.sub.2 :M.sub.2 O mole ratio of from about 1.4:1 to about 2.7:1 wherein M is sodium or potassium. The alkali metal silicate is said to be effective in controlling the detrimental effect of magnesium ion hardness in the wash solution.
It is an object of the present invention to provide granular detergent compositions containing water-insoluble aluminosilicate ion exchange materials and levels of alkali metal oxide silicate solids capable of providing effective corrosion inhibition in free-flowing granules.
It is a further object of this invention to provide detergent compositions containing water-insoluble aluminosilicates and alkali metal oxide silicate solids that do not provide a problem of fabric appearance due to deposition of insoluble material.
It is a still further object of this invention to provide a process for making said detergent compositions.